plant cell

The most prominent feature is the nucleus (1), which contains the
cell's DNA, normally arranged in thin strands called chromatin (2).
Messenger molecules copied from the DNA pass through pores in the
nuclear membrane (3); they then attach themselves to ribosomes (4),
where they direct the synthesis of new cell proteins. Ribosomes are
anchored to parallel membranes – the endoplasmic reticulum (5)
#8211; that form a maze-like network in the cell. Endoplasmic reticulum
may lack ribosomes, in which case it is called smooth endoplasmic
reticulum (6). Plant cells additionally contain chloroplasts (7) and
enzyme-containing microtubules (8). The solution of biological molecules
outside the nucleus is the cytoplasm (9), which is connected to adjacent
cells by plasmodesmata (10). Mitochondria (11), lysosomes (12), and
Golgi bodies (13) are common to all cells, as are the microfilaments
and microtubules (14) that form the cell's internal skeleton.

A typical plant cell

Comparison of animal and plant cells

Both animal (A) and plant (B) cells have a cell membrane (1), nucleus
(2), and cytoplasm (3). But in plants there is also a cell wall (4)
and certain organelles, notably chloroplasts, which are unique to
plant cells

Plant cells come in wide variety of shapes and sizes, and
not all contain every feature of described below. However, they all are
surrounded by an inflexible cell wall, made of cellulose, on the outside
of the cell membrane. The earliest plant cells are thought to have formed
more than a billion years ago, when cells that fed on the nutrients in the
oceans at that time were colonized by bacteria capable of photosynthesis.

Like all eukaryotic cells, including animal cells, plant cells contain membrane-bounded organelles. Some of these organelles,
and other structures, are common to all eukaryotes, while others are found
in plant cells but not in animal cells. Among the distinguishing features
of plant cells are:

Plant cell organelles

plastids: a group of organelles
characterized by a double membrane envelope and a complex of internal
membranes. Plastids contain DNA and replicate
autonomously. Among the types of plastids are:

proplastids: specialized
for dividing to form new plastid, usually found in meristematic
cells